Worth mentioning that most ISPs tell you their speed in bps (bits per second) where-as Steam shows the speed as Bps (Bytes per second), to convert from B to b you multiply by 8, so 300KBps is the equivalent of your ISP being at around 2.4Mbps.

But yes, there could also be other factors such as the above, which I won't reitterate, but also look at your ISPs small print, some, like Virgin Media, have a download cap imposed at certain hours of the day and if you exceed that amount they 1/4 your speed for a few hours, which would make sense with the above info if you were on a 10Mbps connection with them and you exceeded your allowance.

Worth mentioning that most ISPs tell you their speed in bps (bits per second) where-as Steam shows the speed as Bps (Bytes per second), to convert from B to b you multiply by 8, so 300KBps is the equivalent of your ISP being at around 2.4Mbps.

But yes, there could also be other factors such as the above, which I won't reitterate, but also look at your ISPs small print, some, like Virgin Media, have a download cap imposed at certain hours of the day and if you exceed that amount they 1/4 your speed for a few hours, which would make sense with the above info if you were on a 10Mbps connection with them and you exceeded your allowance.

In addition, it may help going into your Steam settings, clicking on the "Downloads+Cloud" tab and checking whether you are connecting to a local server. This is usually auto-detected, but I've had it try to connect me (UK) to east coast US servers in the past.

Might not make much difference, but could possibly be worth checking if you're having difficulties.